The present invention relates to a method of producing a sheet or plate-shaped structure as the bearing material for slide bearings.
German Pat. No. 683,764 discloses the production of bimetal bearing shells by galvanically, or electrolytically, depositing a layer of the bearing metal or of the bearing alloy on a hard metal substrate. However, such bearings are not structured and therefore have no self-lubricating properties.
For the production of self-lubricating slide bearings, it is known to apply a layer of a bearing material, e.g. bronze, in sintered form onto a substrate constituted, for example, by a steel foil or plate. Into this sintered and thus porous material, a lubricant is rolled, e.g. in the form of a mixture of polytetrafluoroethylene (PTFE) and lead (see product brochure entitled Permaglide.RTM. Gleitlager, by Karl Schmidt GmbH, Neckarsulm (March, 1983). However, the ratio of supporting material surface area to lubricant discharging surface area is here substantially given by the selection of the material and the sintering process and can therefore be varied only within narrow limits. Moreover, as a result of the specific manufacturing process, the different size material surface regions and the different size lubricant emitting surface regions are distributed somewhat at random. As a consequence, no optimum conditions exist in the partial regions either for lubrication or for supporting capability.
The publication entitled "Haus der Technik-Vortragsver-offentlichungen" [Published Lectures From The House Of Technology], No. 269 (1971) published by Vulkan Verlag Dr. W. Classen, Essen, pages 61-67, discloses a bearing bush made of a cast copper alloy in which a solid lubricant disposed in pockets or other recesses in the bearing face takes over the lubricating task. According to U.S. Pat. No. 3,938,868, ceramic materials may also be used as bearing material.
FRG-OS No. 2,234,428, and counterpart U.S. Pat. No. 3,976,342, disclose the insertion of a perforated intermediate layer of metal, plastic or a self-lubricating material between faces moving relative to one another and filling the cavities with lubricant. The faces themselves may also be provided with fine recesses in that the surface is given a profile by mechanical, chemical, electrochemical or electrical treatment methods, with such a profile then being rolled over, machined over or ground over. In this way, it is possible to produce structures in a pattern of, for example, circular or cross-shaped recesses, with the minimum distance between edges and the width of the bars being about 0.1 mm and 0.2 mm, respectively. This publication further mentions that it is important to place the cavities or recesses close to one another. However, with the above treatment methods it is not possible to fabricate structures having even smaller distances between edges and smaller bar widths, respectively, under consideration of the required structural depth.